ECHINOCACTUS. 



173 



Not uncommon from southern Coahuila to Zacatecas. Professor F. E. Lloyd states 

 that it is the most striking cactus in northern Zacatecas where it is found on the higher 

 foothill slopes and on the hills on the slopes facing the south, with only very few exceptions. 



Illustrations: Cact. Journ. 1: pi. for August, as Echinocactus saltillcnsis; Mollers 

 Deutsche Gart. Zeit. 25: 485. f. 18, as Echinocactus ingens subinermis; Contr. U. S. Nat. 

 Herb. 12: pi. 23; Ann. Rep. Smiths. Inst. 1908: pi. 8; pi. 13, f. 1 ; Stand. Cycl. Hort. Bailey 

 2:f. 1373. 



Figure 188 is from a photograph of a potted plant from San Luis Potosi, Mexico, 

 collected by Dr. E. Palmer and photographed by Coney Doyle; figure 189 is from a photo- 

 graph of a piece of a rib from near the top of an old plant collected by Dr. E. Palmer in 

 1904 (No. 314). 



Fig. 190. Echinocactus xeranthemoides. 



7. Echinocactus xeranthemoides (Coulter) Engelmann in Rydberg, Fl. Rocky Mountains 579. 1917. 

 Echinocactus polycephahis xeranthemoides Coulter, Contr. U. S. Nat. Herb. 3: 358. 1896. 

 Cespitose, the stems globose, 2.5 to 18 cm. high, light green; ribs 13, interrupted or somewhat 

 tubercled, sharp on the margin ; areoles circular, about 1 cm. in diameter, often less than 2 cm. apart; 

 spines 10 to 15, when young whitish pink, but in age a dirty gray, slender and rather stiff, more or less 

 annulate; radial spines 3 to 4 cm. long, more or less curved backwards; central spines 4, 3 to 6 

 cm. long; one of them longer than the others, somewhat curved, rather stiff; flowers bright yellow, 5 

 cm. long; scales on the ovary and flower- tube linear, pink, papery, stiff, but not pungent, the longer 

 ones 2 to 3 cm. long, persistent; perianth-segments narrowly oblong, more or less serrate, apiculate or 

 cuspidate; stamens included; style yellow (?), included; fruit shortly oblong, 3 cm. long, densely and 

 permanently white-woolly, dehiscing by a basal pore; seeds brownish black, shining, delicately 

 reticulate, 2.5 mm. long. 



